The roughness to slope ratio proposed by Aita, Iwakura, and Husimi in [1]}, can be re-interpreted in terms of the local measure of roughness of the surface of a solid material or an irregular interface, i.e. as the root mean square surface width in function of the height at a given place on the surface (see for example [2]}). In our case if we assume that the “height” is equivalent to the value of the fitness \(f({\bf x})\)  of genotype \({\bf x}\) , and “the place on the surface” corresponds to a domain (on the surface) of the fitness landscape, then we can define the measure of local roughness given a genome \({\bf {x}}\in \lbrace 0,1\rbrace ^N\)  as:
\(\xi _\nu ({\bf x}):= \left( \frac{1}{|{E}(m_\nu (\bf {x})|}\sum _{{({\bf x}},{\bf y}) \in {E}(m_\nu ({\bf {x}}))} \left(f_\nu ({\bf x}) - f_\nu ({\bf y}) \right)^2\right)^{\frac{1}{2}}, \forall {\bf x}\in \lbrace 0,1\rbrace ^N,\) 
